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Hafod Foundations.

.With the snow all gone for now and the ground a bit squidgy I've finally been able to start on the build process for getting the 2nd geo dome (Hafod) up in place. As with most structural projects, the first thing is to start off going down rather than up and this involves digging which I loathe and avoid if I can but needs must.

The first stage in setting up the Hafod is creating a level base that can become the floor. I try to walk lightly on the world and to that end avoid the use of concrete if I can therefore, the dome floor will be made using wooden joists covered with boarding and the joists need to be secured above ground level. Because native bedrock is very close to the surface here you only need to remove a thin covering of soil to get to solid foundation level.

The Geodome structure has 15 feet and the floor to support this will have 15 radial joists like the spokes of a wheel. Around the perimeter each joist will sit on a stainless steel threaded rod, but to avoid having 15 rods close together in the center I have a "cunning plan" (Baldric).

I dug out a square of soil in the center about 1500mm X 1500mm and then drilled 9 holes into the bedrock. Into these holes I secured stainless steel threaded rod each rod having a nut and 50mm square washer set to the same level. Lastly a 1200x1200mm sheet of 6 mm steel plate with suitable drilled holes was set on the studs. Now the 15 joists can terminate on the level plate and the outer ends will sit on an outer stud. With this method the joists can all be levelled by adjusting the nuts up or down on the threaded rods.

The joists I'm using were obtained from a building site where the contractor had made a measuring boob. They are an engineered wooden product called TJI joists and are stronger, lighter and capable of longer unsupported spans, making them very suitable for my purpose. Plus they were a bargain as the contractor wanted shot of the evidence of his boob. Each joist is 5 mtr long so will be cut to just under 3mtr. to give the required dome radius.

Anyhow Katherine and I got the steel plate (60Kg or so) across the field using the trailer on the new quad and got it and all the studs in place along with 11 of the perimeter studs. An hour or so on Monday should see the last few done. The TJI joists are currently stored in our Poly tunnel and so as they come out from their winter storage it will clear a space for K to get on with this years planting and planning! Double cunning huh.

We (K) also did some more work on the pond. After due consideration we decided that the pond area could be greater so K set to work with a mattock to remove more of the marsh grass before extending the pond liner and replacing the sodden clods of marshy soil. It was quite a childish pleasure squelching around knee deep in liquid mud. In warmer weather we could probably charge for this as a beauty treatment. Being an equal opportunity employer I do like to share all the good jobs about!

The new quad has proved to be a real boon allowing me to cart all the tools, drills and materials over to the dome site and back at day’s end, so everything is kept tidy. I don’t think Muffin is ever going to ride on the bike but he does love it when we’re busy outside and he can help by digging holes everywhere. Although today we did manage a walk in some nearby forest after dropping paper work over at our storage yard so he got to dig holes in some one else fields.

The week here has been mainly windy and drying up although more rain is soon the way apparently.

Wind turbine power generated this week 33.4 KwHrs

PV power generated this week 9.2 KwHrs.

Total renewable energy created on site week 42.6 KwHrs

On the decks this week I’ve had Blazin Fiddles. They are a Scottish fiddle band we went to see live in winter 2019. They set your feet tapping and you can see why a Shetland wedding can last 2 days with dancing and drinking all night; why would you stop! Turned out I had met the mother of one of the girl fiddlers when I worked in Shetland back in the 1970’s. Wow. Try this


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